Staff have been sent memos about the change – and even sent on training courses.

But charities representing epileptics have branded the move political correctness gone mad.

Margaret Thomas, of the National Society for Epilepsy, said: “Brainstorming is a clear and descriptive phrase. Alternatives such as ‘thought shower’ or ‘blue-sky thinking’ are ambiguous to say the least. Any implication that the word ‘brainstorming’ is offensive to epileptics takes political correctness too far.”

Epilepsy causes seizures, like a “storm” of activity in the brain.

But Richard Colwill, of mental health charity SANE, said: “This ban goes too far. Few would be genuinely offended by the word ‘brainstorming’ in the context of council meetings.”